Fractures across long bones, such as the femur or tibia, as well as fractures of other bones, such as the humerus or bones in the ankle/hind foot region, are fairly common. These fractures may result in two or more portions of bone that need to be compressed and held together during the healing process. Fracture fixation of such portions can be challenging because of the difficulty of properly aligning and then securing fractured bone segments in place to allow the bone to heal. The bone fragments may be secured using a bone plate or an intramedullary nail (with or without compression) or using other implants and/or instrumentation.
Whether fixation uses an intramedullary nail, bone plate, or other types of implants, the reduction of the segments of a long bone fracture may be a critical aspect of fracture fixation. Reduction can be important to ensure that the bone will heal properly and more quickly, to decrease pain and prevent deformity, and to allow the patient to regain use of the bone and limb. When intramedullary nails or bone plates are implanted to treat fractures, there is a need to reduce a fracture with a high level of control and accuracy. Additionally, it may be desirable to reduce the fracture using a minimally invasive procedure. Finally, it may also be important to leave the two portions of the bone in a compressed state to ensure proper and quick healing.
Typically, when an implant, such as an intramedullary nail or bone plate, is used, the surgeon will position the implant so that the implant traverses or extends across the fracture between the two portions of the bone. Once this is done, the surgeon will typically lock one end of the implant to a bone portion.
After fixing one of the ends of the implant to one of the bone fragments, it may be desirable to reduce the fracture. One known method for reducing the fracture is for the surgeon to “back-slap” a drill guide attached to the implant. While reduction may occur, this method is not optimal. First, a “back-slap” is not a controlled reduction. Second, there is no instrument used to hold the compression between the two portions of the fragmented bone while the proximal end of the implant is locked to the other bone portion, which may lead to locking the bone fragments in a non-compressed state.
Another known method of reducing a fracture is by using an implant with a slot. Once the implant is settled in the correct position of the fracture, a bone screw is inserted and locked into the slot. The fracture is reduced when a compression screw pushes against the locked bone screw, thereby pushing on the implant itself. While this method does allow for control and holds the compression while the other end of the implant is locked, this method brings about other problems. First, the method requires pre-assembly, which constrains the surgeon to plan to use the compression feature before implanting the implant. Second, a load is placed on the bone screw which can cause the screw to flex. Leaving the bone screw in such a post-op state may lead to the screw becoming deformed. Also, this assembly prevents additional screws from being placed in an optimal region of the upper fracture due to the compression screw and slot size occupying the same area on the implant and fracture.
Accordingly, it may be desirable to provide instrumentation and implants that allow for efficient, controlled, and accurate reduction of a fracture. It may also be desirable for such a device that does not leave the implant and its components in a state of stress after the fracture has been reduced and the implant locked in place. Further, it may be desirable for the implant and its instrumentation to allow other locking screws to be placed in optimal regions while holding the fracture in a compressed state.